Add AFL++ integration (#379)

The patch implements the required APIs and infra to build
Grammarinator-driven custom AFL++ mutators. Beside the basic integration
tasks, Grammarinator is extended with SubTreePool population support,
custom ddmin-based trimming for AFL and two new mutators based on the new
population approach.

Author: renatahodovan

grammarinator-cxx/CMakeLists.txt

@@ -1,4 +1,4 @@
-# Copyright (c) 2025 Renata Hodovan, Akos Kiss.
+# Copyright (c) 2025-2026 Renata Hodovan, Akos Kiss.
 #
 # Licensed under the BSD 3-Clause License
 # <LICENSE.rst or https://opensource.org/licenses/BSD-3-Clause>.
@@ -12,6 +12,7 @@ option(GRAMMARINATOR_GENERATE "build generator tool" OFF)
 option(GRAMMARINATOR_DECODE "build decoder tool" OFF)
 option(GRAMMARINATOR_FUZZNULL "build fuzznull tool" OFF)
 option(GRAMMARINATOR_GRLF "build libgrlf" OFF)
+option(GRAMMARINATOR_GRAFL "build libgrafl" OFF)
 
 set(GRAMMARINATOR_GENERATOR "" CACHE STRING "name of the generator class created by grammarinator-process (mandatory for specialized artefacts)")
 set(GRAMMARINATOR_MODEL "" CACHE STRING "name of the decision model class (for specialized artefacts)")
@@ -71,8 +72,9 @@ grammarinator_status(GRAMMARINATOR_GENERATE)
 grammarinator_status(GRAMMARINATOR_DECODE)
 grammarinator_status(GRAMMARINATOR_FUZZNULL)
 grammarinator_status(GRAMMARINATOR_GRLF)
+grammarinator_status(GRAMMARINATOR_GRAFL)
 
-if(GRAMMARINATOR_GENERATE OR GRAMMARINATOR_DECODE OR GRAMMARINATOR_FUZZNULL OR GRAMMARINATOR_GRLF)
+if(GRAMMARINATOR_GENERATE OR GRAMMARINATOR_DECODE OR GRAMMARINATOR_FUZZNULL OR GRAMMARINATOR_GRLF OR GRAMMARINATOR_GRAFL)
   if ("${GRAMMARINATOR_SUFFIX}" STREQUAL "")
     set(GRAMMARINATOR_SUFFIX "${GRAMMARINATOR_GENERATOR}")
     string(TOLOWER "${GRAMMARINATOR_SUFFIX}" GRAMMARINATOR_SUFFIX)
@@ -126,6 +128,9 @@ add_subdirectory(libgrammarinator)
 if(GRAMMARINATOR_GRLF)
   add_subdirectory(libgrlf)
 endif()
+if(GRAMMARINATOR_GRAFL)
+  add_subdirectory(libgrafl)
+endif()
 if(GRAMMARINATOR_GENERATE OR GRAMMARINATOR_DECODE OR GRAMMARINATOR_FUZZNULL)
   add_subdirectory(tools)
 endif()

grammarinator-cxx/dev/build.py

@@ -31,21 +31,25 @@ def build_options_append(cmakeopt, cliarg):
     build_options_append('GRAMMARINATOR_DECODE', 'ON' if args.decode else 'OFF')
     build_options_append('GRAMMARINATOR_FUZZNULL', 'ON' if args.fuzznull else 'OFF')
     build_options_append('GRAMMARINATOR_GRLF', 'ON' if args.grlf else 'OFF')
+    build_options_append('GRAMMARINATOR_GRAFL', 'ON' if args.grafl else 'OFF')
 
-    if args.generate or args.fuzznull or args.grlf:
+    if args.generate or args.fuzznull or args.grlf or args.grafl:
         build_options_append('GRAMMARINATOR_GENERATOR', args.generator)
         build_options_append('GRAMMARINATOR_MODEL', args.model)
         build_options_append('GRAMMARINATOR_LISTENER', args.listener)
         build_options_append('GRAMMARINATOR_TRANSFORMER', args.transformer)
 
-    if args.generate or args.decode or args.fuzznull or args.grlf:
+    if args.generate or args.decode or args.fuzznull or args.grlf or args.grafl:
         build_options_append('GRAMMARINATOR_SERIALIZER', args.serializer)
         build_options_append('GRAMMARINATOR_TREECODEC', args.treecodec)
         build_options_append('GRAMMARINATOR_INCLUDE', args.include)
         build_options_append('GRAMMARINATOR_INCLUDEDIRS', ';'.join(os.path.abspath(includedir) for includedir in args.includedir))
         build_options_append('GRAMMARINATOR_SUFFIX', args.suffix)
         build_options_append('GRAMMARINATOR_LOG_LEVEL', args.log_level)
 
+    if args.grafl:
+        build_options_append('GRAMMARINATOR_AFL_INCLUDEDIR', os.path.abspath(args.afl_includedir))
+
     return build_options
 
 
@@ -109,6 +113,10 @@ def main():
                       help='build a dummy fuzznull binary to test libFuzzer integration without a real fuzz target (default: %(default)s)')
     sgrp.add_argument('--grlf', default=False, action='store_true',
                       help='build a static libgrlf library for libFuzzer integration (default: %(default)s)')
+    sgrp.add_argument('--grafl', default=False, action='store_true',
+                      help='build a shared libgrafl library for AFL++ integration (default: %(default)s)')
+    sgrp.add_argument('--afl-includedir', metavar='DIR',
+                      help='AFL include directory (mandatory if --grafl is specified)')
     sgrp.add_argument('--generator', metavar='NAME',
                       help='name of the generator class')
     sgrp.add_argument('--model', metavar='NAME',
@@ -134,12 +142,16 @@ def main():
         'json': 'JsonTreeCodec'
     }[args.tree_format] if args.tree_format else None
 
-    if args.generate or args.fuzznull or args.grlf:
+    if args.generate or args.fuzznull or args.grlf or args.grafl:
         if not args.includedir or (not args.generator and not args.include):
             parser.error('To build specialized artefacts, either the `--generator` or the `--include`, and the `--includedir` arguments must be defined.')
         if not args.generator and not args.suffix:
             sys.stderr.write(f'{parser.prog}: Neither `--generator` nor `--suffix` is defined; the created binary will get a default name.\n')
 
+    if args.grafl:
+        if not args.afl_includedir:
+            parser.error('To build AFL integration, the `--afl-includedir` argument must be defined.')
+
     try:
         configure_cmake(args)
         cmake_build(args)

grammarinator-cxx/libgrafl/CMakeLists.txt

@@ -0,0 +1,22 @@
+# Copyright (c) 2025-2026 Renata Hodovan, Akos Kiss.
+#
+# Licensed under the BSD 3-Clause License
+# <LICENSE.rst or https://opensource.org/licenses/BSD-3-Clause>.
+# This file may not be copied, modified, or distributed except
+# according to those terms.
+
+grammarinator_spec_target_name(GRAFL grafl)
+add_library(${GRAFL} SHARED grafl.cpp)
+if(NOT DEFINED GRAMMARINATOR_AFL_INCLUDEDIR)
+  message(FATAL_ERROR "GRAMMARINATOR_AFL_INCLUDEDIR not set.")
+endif()
+target_include_directories(${GRAFL} PRIVATE ${GRAMMARINATOR_AFL_INCLUDEDIR})
+grammarinator_spec_definitions(${GRAFL})
+target_link_libraries(${GRAFL} PRIVATE grammarinator)
+
+configure_file(libgrafl.pc.in lib${GRAFL}.pc @ONLY)
+
+install(TARGETS ${GRAFL} DESTINATION lib)
+install(FILES ${CMAKE_CURRENT_BINARY_DIR}/lib${GRAFL}.pc DESTINATION lib/pkgconfig)
+
+set(GRAFL ${GRAFL} PARENT_SCOPE)